Stenobiont

Part of speech: noun, adjective

Definitions

1. An organism that can survive only within a very narrow range of environmental conditions such as temperature, moisture or salinity
2. A species that is limited to a small set of habitat conditions and cannot tolerate wider variation in its surroundings
3. Any living thing with a tightly restricted tolerance for changes in its environment, so it thrives only in specific narrow conditions

Etymology: "Stenobiont" is built from two Greek elements. "Steno-" comes from Greek "stenos", meaning narrow or confined, and "-biont" comes from Greek "biont", from "bion", meaning living thing or life. Put together, the word describes an organism that lives within a narrow range of conditions, such as a particular temperature, salinity, or food source. The two halves work in a common pattern in biology. Ecologists pair "steno-" with "-biont" to contrast with the opposite idea, "eurybiont", formed from Greek "eurys", meaning wide. A stenobiont can survive only in a tightly limited habitat, while a eurybiont tolerates a broad range of conditions. The pairing is a modern scientific coinage from classical roots, not a term that Greek speakers themselves used.